1. Field of the Invention
The invention relates to methods and apparatus for attaching two components of a fastener to a garment or to a compliant sheet of material in sandwich configuration without puckering or wrinkling the material.
2. Description of the Prior Art
The prior art, as exemplified by U.S. Pat. Nos. 2,071,507, 2,310,007, 4,309,806, and 4,454,650 contains a number of methods and apparatus for applying a fastener member to sheet material that is maintained in a relatively taut or tensioned condition as the prongs pierce the material and are received in the fastener member. In Dews, U.S. Pat. No. 2,071,507, a snap fastener is applied to an elastic sheet material in which the sheet material is stretched over an eyelet member, perforated at the tip after which the elastic material snaps down the post towards the base of the eyelet. A stud is clamped thereon and the sheet material, because it has been stretched and perforated snaps to a smooth plane. U.S. Pat. No. 2,310,007 has a plurality of clamps that attempt to maintain the material in position, but the material tends to give when the prongs penetrate therethrough, resulting in some puckering or wrinkling around the fastener element. As shown and described in U.S. Pat. No. 4,309,806, a flexible circular member affixed to the socket member engages the material and tends to urge the sheet material circumscribed thereby into a stretched position as the prong members penetrate the material. Silver, U.S. Pat. No. 4,454,650 drives the upper component of the fastener through an opening in the table that is substantially larger than either the upper or lower component and unto a stationary lower component immediately beneath the fabric, which fabric is not held so as to be stretched taut over the opening. However, the prior art methods and apparatus are limited to frictionally holding a sheet of material in a given plane as shown in U.S. Pat. Nos. 2,310,007 and 4,309,806; or require deformation of an elastic sheet material that snaps into position once it is perforated as shown in U.S. Pat. No. 2,071,507; or drive the upper component and material onto a stationary lower component without the material being held in place as shown in U.S. Pat. No. 4,454,650.
As described hereinafter, the subject invention avoids wrinkling of the sheet material after the application of a fastener member thereto.